Press



Oct. 3, 1944. R. T. POLLOCK PRESS 2 Sheets-Sheet 1 Filed Feb. 26, 1943Jhven-Yvr ROBERT T. POL LOCK Oct. 3, 1944. R T, K 2,359,674

. PRESS I Filed Feb. 26, 1943 2 Sheets-Sheet 2 if; 3 HE- Patented Oct.3, 1944 PRESS Robert T. Pollock, New York, N. Y., assignor to MaguireIndustries, Incorporated, a. corpora tion of New York ApplicationFebruary 26, 1943, Serial No. 477,289

4 Claims.

My invention relates to a press, and more particularly a press wherein aplunger enters a die. The invention is especially useful in connectionwith an apparatus wherein loosely packed material is compressed. into ahard, firm cake, to which. use the invention is not restricted.

One object of the invention is to provide a press which will exertpositive uncushioned force upon a substance to be pressed. Anotherobject is the provision of a press, of the class described, wherein airwill be released as the punch enters th die and compresses the materialtherein. A further object is to provide such a press which will permitrelease of such air without loss of material from the die. Other objectswill be ap arent upon consideration of the present speciflcation.

The invention is shown by way of illustration in its embodiment in apress for forming foodstuffs into cakes in the accompanying drawings,wherein- Figure 1 is a perspective view of a press cnstructed inaccordance with the invention;

Figure 2 is a vertical section through the die illustrated in Figure 1,showing in elevation the plungers and the compressed material therein;

Figure 3 is a vertical half mid section through the die, the'plungersand the compressed material illustrated in Fig. 2;

Figure 4 is a horizontal cross section taken on the line IV-IV of Fig.2;

Figure 5 is an end view of the compression face of one of the plunger-s;

Figure 6 is a vertical section similar to Fig. 2, illustrating anotherform of the plungers; and

Figure 7 is a cross section of the upper plunger illustrated in Fig. *6,taken on the line VII--VII of Fig. 6.

In pressing material in a die, difficulty is frequently experiencedbecause of air which is entrapped as th plunger enters the die. Air soentrapped maycushion the pressure of the plunger, preventing properaction upon the material, which is necessary to form a smooth surfaceand a uniformly compacted block. Furthermore, such entrapped air maycause a rebound of the plunger, which is particularly undesirable incertain types of press. Finally, in pressing loosely packed material,such as certain foodstuffs, into a compact cake, the cake may actuallydisintegrate when the pressure is released.

In the past, attempts have been made to overcome this difliculty byforming orifices in the walls of the die or in the compression face ofthe plunger, but such orifices necessarily become the bed plate ill, aswill clogged or filled with the substance under compression, andcontinuously repeated pressing operations must be periodically halted inorder to clean these orifices. Furthermore, such orifices in the formingsurfaces of a press tend to mar the smooth firm face which is sodesirable on the pressed cake.

The present invention provides a press wherein entrapped air may leavethe die in suiiicient quantities to eliminate the above-mentioneddifficulties, and wherein a substantially uniform, solid cake, withsmooth, firm faces, may be produced.

In the drawings there is shown a press comprising a bed plate Ill, and adie ll positioned with its upper surface flush with the upper surface ofsaid bed plate. A pair of plungers are movable in said die with theusual small clearances between their sides and the inner walls of thedie. In order to facilitate escape of air from the die during thepressing operation the plungers are formed in a manner later to bedescribed.

The upper plunger here shown is a punch II, which may be moved into andout of the die II, by means of an upper ram I 3 actuated by any known orconvenient press mechanism. The lower plunger is illustrated as a bunterI, reciprocable within the die and carried by a lower ram i5, which isoperated by known press mechanism. As here shown, the lower ram isoperated by a forked lever It the end of which rests upon a stop I! whenthe bunter is in its lowermost position. The lever i8 periodically liftsthe bunter until its upper face lies in the plane of be hereinafter morefully described.

The material to be pressedas descrete elements of foodstuff-is placed ina hopper i8 which is carried by the press above the bed plate iii. Thehopper l8 terminates in an annular neck I! at its lower end. Immediatelybeneath the neck I9, is a feeder 20 which rests upon the bed plate l0and is pivoted thereto concentrically with the axis of the neck It. Thefeeder comprises a central support 2i, from the base of which threeangularly disposed radial arms 22, 23, 24 extend along the bed plateIt], upon which they rest. The feeder 20 is thus pivoted, immediatelybeneath the hopper l8, to the bed plate i0, upon which it is supportedin a state of equilibrium in all positions. The radial arm 22 actsmerely as a support for the feeder. The arm 23 acts as a suppo t andalso has pivoted to its outer end, in well known manner, the end of anactuating rod 25. A conduit 26 is carried .plane of the bed plate.

by the central support 2| and the radial arm 24. The conduit 26 passesthrough the radial arm 24 to form a lower opening which is normallyclosed by the bed plate lllupon which the arm 24 rests.- This loweropening is preferably larger than the opening in the die II. The upperend of the conduit 26 is fitted to the neck IQ for turning thereabout.

Thus, the hopper l8 being filled with foodstuff, the conduit 26 isimmediately also filled thereby, contact of the lower end of the conduitagainst the bed plate l preventing the flow of foodstuff therefrom.

The die ll being filled with the foodstuff, and

the bunter 14 being in its lowermost position with the forked lever l6resting upon the stop ll, the press is started. The upper ram l3 pressesthe punch l2 into the die thereby compressing the loose foodstufftherein into a solid, compact cake. As the punch is withdrawn, thebunter is raised by the forked lever l6 until its upper face lies flushwith the upper face of the die II in the Thereupon, the compressed cakeis positioned above the die and the bed plate. Tension is now applied bythe press to the actuating rod 25, thereby turning the feeder 20 aboutits pivot in a clockwise direction, as seen in Figure 1. Thus theleading edge of the arm 24 pushes the formed cake off the top of thehunter and away from the die. As the lower end of the conduit 26 ispositioned over the top of the die H, the die is filled with foodstufffrom the conduit. Compression is now applied by the press to theactuating rod 25, the feeder returns to the position illustrated inFigure 1, and the cycle is repeated.

If the plungers are of usual construction air will be compressed betweenthem during the pressing operation with the results noted above.Furthermore, the press must then be operated at a slow rate of speed ifanything approaching satisfactory results are to be attained in pressingloosely packed or porous material. By reducing the cross section of theplungers back of their operating end faces, it is possible tofacilitate'escape of air from the die during the forming operation.

As illustrated in Figs. 2 and 3, each side face 21 of the punch 12 has adepression 28 formed therein. The depressions 28 preferably extend intoclose proximity to the operating end face 29 of the punch, where thefull section is provided. In the embodiment illustrated in Figs. 1 to 5,inclusive, only the longitudinal edges and the extreme front and rearportions of the punch are r not cut away. Similarly, the hunter M has adepression 30 formed in each of its side faces. Like depressions 28 inthe side faces of the punch,

the depressions 30 preferably extend into close proximity to theoperating end face of the hunter.

Without limiting the invention to any particular dimensions orproportions, it may be stated that in one successfully operatedembodiment the die. Furthermore, the depressions extended to withintwenty-five thousandths of an inch of the operating end face of eachplunger. Manifestly other dimensions and proportions might be used-as,indeed, they have been, with complete success. In general the plunger orpunch is always of full cross section immediately back of its operatingend face for a distance of less than half of the smallest dimension ofits operating end face, and is of reduced section back of this fullsection.

It is preferred to dish the operating end faces of the plunger, as isbest shown at 3| and 32 in Fig. 3, in order to form ,beveled faces onthe pressed cake.

Finally, the depression in each side face of the plunger need notconsist of a single reduction in section as illustrated in Figs. 1 to 4,but may comprise a series of longitudinal flutes. Figs. 6 and '7illustrate such a construction wherein the flutes 33 extend into closeproximity to the operating end face of each plunger, as do thecontinuous depressions previously described.

By providing the usual clearances between the die and the plunger at theoperating and face thereof, material in the die may be formed withoutloss in the usual way. At the same time, by providing a comparativelyunrestricted air passage extending away from the point of compressionfrom close proximity to the operating end face of the plunger, escape ofair from the die is facilitated.

The forms of the invention herein described and illustrated in theaccompanying drawings are presented merely by way of illustration. Otherforms of the invention will readily suggest themselves to those dealingwith such problems, which do not depart from the invention or the properscope of the appended claims.

40 I claim:

clearance between the full section of the plunger and the die wastwenty-five ten-thousandths of an inch, and the depressions in the sidefaces of the plunger provided a clearance of nine-hundredths of an inchbetween the plunger and the 1. A press comprising a die, a plungermovable in said die to form material therein, and means for operatingsaid plunger, said plunger having a depression in a side face thereofextending to within a distance of the order of twenty-five thousandthsof an inch back of its operating face to facilitate escape of air fromsaid die during the forming operation.

2. A press comprising a die, a plunger movable in said die to formmaterial therein, and means for operating said plunger, said plungerhaving a depression of the order of nine hundredths of an inch in a sideface thereof extending to within a distance of the order of twenty-fivethousandths of an inch back of its operating face to facilitate escapeof air from said die during the forming operation.

3. For use with a press, a punch having a depression in each side facethereof extending to within a distance of the order of twenty-fivethousandths of an inch from its operating end face.

4. For use with a press, a punch having a depression of the order ofnine hundredths of an inch in a side face thereof extending to within a.distance of the order of twenty-five thousandths of an inch from itsoperating face.

ROBERT T. POLLOCK.

